Field of the Invention
This invention pertains to the field of equipment for conveying and has as its object a particular conveying device, as well as a method for using such a device.
The movement of products, in a conveying and handling line, can, depending on the needs, take place either in a single line, the products being then aligned one behind the other in a single column or line, or in bulk, the products then being able also to be next to one another, according to a more or less structured arrangement. A single-line movement is, for example, necessary as long as the products must be handled by unit, for labeling or counting, for example. A movement in bulk is selected in particular to ensure accumulation functions, to reduce the length of the equipment, or even to reduce the travel speed of the products while preserving an overall flow rate.
Equipment is then necessary to ensure the transitions between these two conveying forms: an aligner thus has the function of making the products go from a bulk configuration to a single-line configuration, and therefore of reducing the number of columns of products, and a deconsolidator has the reverse function, namely that of increasing the number of columns, in particular to make the products go from a single-line configuration to a bulk configuration. The invention relates more particularly to the deconsolidators.
Description of the Related Art
Generally, a deconsolidator has, on the one hand, a speed differential between two conveying portions, namely a fast conveying portion and a slower conveying portion, thus causing the products to be positioned side-by-side to preserve the overall flow rate, and, on the other hand, means for making the products go from the fast portion to the slow portion. FR2531046 thus discloses the use of an inclined plane to transfer the products from the fast portion to the slow portion. A robust operation, however, is very difficult to attain at high speeds by using gravity. Mechanical guides are preferred today to ensure the passing from one portion to the next.
Thus, embodiments are known that are in the form of a deconsolidator arranged in an angular zone of a conveyor. The products travel in a single line in the fast portion, and the passing of the products from the fast portion to the slow portion takes place in the curve of the conveyor, where the fast portion is formed by the zone with a small radius of curvature, and the slow portion is formed by a series of lines in the zone of the higher radii of curvature. This embodiment has numerous drawbacks. Actually, it can more easily lead to falls of products during the passing from one conveyor to the next, because of the greater separation between curved conveyors, resulting in particular from higher wear. Furthermore, because of the curved shape, the driving direction in the slow portion is not uniform, which destabilizes the products more, in particular at high speed. Finally, in such a configuration, an effective deconsolidation can be achieved only if the angle between the two directions of speed is significant. At high speed, the falls are then very frequent.
From FR2604693, a solution is also known for multistage deconsolidation on parallel conveyors, in which the products arrive in a single line, then travel gradually transversely in a first conveyor having a sequence of two zones with a speed differential, then arrive on a second output conveyor, at a still lower speed. In the first conveyor, the products are both slowed and moved transversely, which, at high speed, easily causes falls. Furthermore, to redirect the products transversely at the same time as they are slowed necessitates the use of guides. Under the effect of the braking, the slowed products thus accumulate gradually against these guides and the pressure in this column can reach values such that the column breaks up and a product is then violently ejected transversely. It is therefore not possible, with this type of embodiment, to attain high speeds and to deconsolidate over a short conveying distance, necessitating significant speed gradients.
U.S. Pat. No. 4,308,944 also has a multistage deconsolidation, in which the products travel on parallel conveyors that have a speed gradient, while going each time from a fast conveyor to a slow conveyor thanks to an angled guide, along which the products accumulate until creating the problem already mentioned above of the breaking up of the column of products. A multistage slowing of the products leads to excessive lengths for the entire device. Moreover, this embodiment illustrates a particularly problematic phenomenon at high speed: the end portion of the guide must be extended transversely to the direction of advance to cause the products to go as quickly as possible to the slow portion, but at high speed, the more transverse this end portion is, the more the products run the risk of being thrown against the opposite guide and falling. Furthermore, a violent transverse deflection increases the pressure within the column of products upstream, destabilizes the products more, and intensifies the harmful centrifugal phenomena once the product is freed from the guide.
Finally, other deconsolidator-type embodiments are also known, essentially in the form of two linear conveying zones that are parallel and side-by-side, having a speed differential relative to one another, the fastest portion having at its terminating end a guide ensuring a transverse deflection of the products toward the slowest portion. This type of embodiment, however, itself also leads to producing simultaneously the reduction in speed and the transverse movement, which destabilizes the products too much at high speed. The pressure along the end guide can also become problematic, as described above.